刷新页面时停止 INSERT INTO 创建新行[重复]答案

【问题标题】：Stop INSERT INTO from creating new row when page is refreshed [duplicate]刷新页面时停止 INSERT INTO 创建新行[重复]
【发布时间】：2014-09-15 04:31:56
【问题描述】：

我在下面有这段代码，它工作正常，除非我刷新页面时它会插入一个空白行。有人知道我需要在这里做什么吗？

<?php
$con=mysqli_connect("localhost","name","password","inventory");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

// escape variables for security
$inv_number = mysqli_real_escape_string($con, $_POST['inv_number']);
$date = mysqli_real_escape_string($con, $_POST['date']);
$date_type = mysqli_real_escape_string($con, $_POST['date_type']);
$item1 = mysqli_real_escape_string($con, $_POST['item1']);
$location1 = mysqli_real_escape_string($con, $_POST['location1']);

$sql="INSERT INTO invoice (inv_number, date, date_type, item1, location1)
VALUES ('$inv_number', '$date', '$date_type', '$item1', '$location1')";

if (!mysqli_query($con,$sql)) {
  die('Error: ' . mysqli_error($con));
}
echo 'Invoice #'.$_POST['inv_number'].' recorded'; 

mysqli_close($con);
?>

我尝试找到可以阻止代码创建空白行的条件 if 语句，但无济于事，我找到了可行的解决方案。

感谢任何帮助。

【问题讨论】：

使用这样的标头('Location: example.com/');
基本上就是这样，您刷新页面，发出另一个请求，再次执行您的 PHP，从而再次插入
if (empty($_POST) == true) { header('位置：返回页面'); }else{ 设置变量并运行查询 }

标签： php mysql database insert-into

【解决方案1】：

<?php
$con=mysqli_connect("localhost","name","password","inventory");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
if (empty($_POST['inv_number']) || empty($_POST['date']) ||empty($_POST['date_type'])
    || empty($_POST['item1']) || empty($_POST['location1'])) 
    {
      echo "Re direct user by using header or show them messages";

    }
else {
    // set your variable and run your query 
    //i just copy and posted your code from your question
// escape variables for security
$inv_number = mysqli_real_escape_string($con, $_POST['inv_number']);
$date = mysqli_real_escape_string($con, $_POST['date']);
$date_type = mysqli_real_escape_string($con, $_POST['date_type']);
$item1 = mysqli_real_escape_string($con, $_POST['item1']);
$location1 = mysqli_real_escape_string($con, $_POST['location1']);

$sql="INSERT INTO invoice (inv_number, date, date_type, item1, location1)
VALUES ('$inv_number', '$date', '$date_type', '$item1', '$location1')";

if (!mysqli_query($con,$sql)) {
  die('Error: ' . mysqli_error($con));
}
echo 'Invoice #'.$_POST['inv_number'].' recorded'; 
}
mysqli_close($con);
?>

请注意，如果 if 语句中给出的任何字段为空，您的查询将不会运行

请阅读解决方案中的评论

【讨论】：